Open end wrench



y 1966 L. E. BODKIN 3,252,359

OPEN END WRENCH Filed March 19, 1964 2 Sheets-Sheet 1 FIG.\

INVENTOR. Lawrence .51 Baa/kin y 1966 E. BODKIN 3,252,359

OPEN END WRENCH Filed March 19, 1964 2 Sheets-Sheet 2 FIG.4

INVENTOR. Lawrence l. Bad/cm y Zea 9234M;

A TTOR/VE) United States Patent 0.

3,252,359 OPEN END WRENCH Lawrence E. Bodkin, 1833 Ryar Road, Jacksonville, Fla. Filed Mar. 19, 1964, Ser. No. 353,219 10 Claims. (Cl. 81119) This invention pertains to fixed jaw wrenches, and particularly to open end wrenches having stepped jaws for turnably engaging polygonal grippable portions of rotatable members such as nuts and boltheads, or portions of rods or shafts of polygonal cross section, or the like, of a range of sizes.

An object of the invention is to provide an improved open end wrench which will ratchet on the polygonal portion of the member being turned.

Another object is to provide an open end wrench which will operate to drivingly engage polygonal shapes of each of a series of sizes.

A specific object is to combine in one pair of jaws of an open end wrench the facility to turninglyengage each of a series of polygonal shapes in a manner to permit ratcheting action on each size, and with the portion of the shape-s engaged by the wrench flats being of optimum extent.

While the invention has applicability to square nuts, boltheads and the like, and while it may be applied to octagonal shapes, it finds its most practical application with hexagonal shapes.

It will be understood that the terms square shapes, polygonal shapes, and hexagonal shapes asused herein are intended to encompass generally nuts, bolt or screw heads, shafts, keys, rods and other mechanical elements or members, or parts thereof, which may be adapted for turning by a wrench and which are, respectively, of

square, regular polygon-a1 or hexagonal outline in cross section, and which have an even number of sides.

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

.FIG. 1' is a plan view of the jaw portion of an open end wrench for'hexagonal shapes in accord with the invention, shown in connection with hexagonal shapes of three different sizes, two of which are presented in broken lines;

FIG. 2 is 'a similar view of the jaws of the wrench of FIG. 1 in driving engagement with a hexagonal shape, and representations of said jaws in broken lines in several positions assumed during backward ratcheting of the wrench and demonstrating the functions thereof;

FIG. 3 is a similar view of the jaws of the wrench of FIGS. 1 and 2 with the wrench inverted and positioned on-the hexagonal shape of FIG. 2 to turn the shape in the direction opposite to the direction in which it would be turned in the FIG. 2 arrangement; and

FIGS. 4 and 5 are views corresponding to FIGS. 1 and 2 but showing the jaw portion of a wrench for square shapes together with representations of such shapes.

As seen in FIG. 1, the wrench 1 comprises a suitable handle 2 rigid with two jaws 3 and 4 extending forwardly, in a direction to the right as viewed in FIG. 1, from the end 5 of the handle, and extending generally outwardly from each other. The jaws are provided with stepped inner faces and, specifically, jaw 3 has an inner face made up of the series of shape-engageable flats 6, 7, 8 and 9, whereas, shape-engageable flats 10, -11 and 12 constitute the operative face portions of jaw 4. Jaw 4 in 3,252,359 Patented May 24, 1966 addition is relieved by a face portion 13 which extends starting from an edge 14 at the rearward and inward terminus of fiat 12, in a rearward direction toward the left as viewed in FIG. 1 and in an outward direction away from the space between the jaws.

Jaw 4 is seen to have a first or outermost fiat 10 which, from a rearward terminal edge 15, extends forwardly and outwardly of the space between the jaws, at approximately thirty degrees .to an approximate center line 16 between the jaws. Flat 10 includes an operative portion 17 which a is arranged to engage a face of a hexagonal shape, such as face 18 of shape 19 shown in broken lines. Forwardly of portion 17, the flat terminates and is relieved outwardly as at 20.

Parallel, or very nearly parallel, to fiat 10 of jaw 4 is a second flat 6 of jaw 3 extending from an outer and rearward edge or terminus 21 of the flat in a direction forwardly of the wrench and inwardly of the space between the jaws at an angle of approximately thirty degrees to center line 16. Flat 6 terminates forwardly in an edge 22 and the jaw 3 is relieved outwardly beyond edge 22 as seen at 23. Flat 11 may be considered to be the third flat, and it meets the first-flat at its rearward terminal edge 15 and extends rearwardly and outwardly from center line 16 to a terminus at 24. The reflex angle between fiat 10 and flat 11 at common edges 15 is 240 degrees, or substantially 240 degrees, and the angle between fiat 11 and center line 16 is approximately 30 degrees;

Parallel to fiat 11 of jaw 4 is the fourth flat 7 of jaw 3 which extends from a juncturewith flat 6 at edge 21 in a direction rearwardly of the wrench, inwardly of the space between the jaws and at angle of degrees, or substantially 120 degrees, 'to flat 6. Flat 7 terminates rearwardly in an edge 25. The angles between adjacent tflats along each jaw referred to herein are measured as the open angle directed toward or facing the space between the jaws rather than the angle measured within the respective jaw element. Thus the arc swung on juncture 2 1, inwardly of the space between the jaws, from fiat 6 to flat 7 measures the angle therebetween as 120 degrees.

The fifth flat 12 on jaw 4 extends from juncture 24 with flat 1 1 rearwardly and inwardly, at an angle of substantially 120 degrees to flat 11 to terminate at edge 14, while sixth flat 8 of jaw 3 extends substantially parallel to flat 12 from edge 25 in a rearward and outward direction, at an angle of substantially 240 degrees to flat 7, this being the reflex angle measured inwardly of the space between the jaws. Flat 8 terminates in a rearward and outer end edge 26. The seventh flat of the wrench shown in FIGS.

1-3 is'flat 9 on jaw 3 which extends from edge 26 in a rearward and inward direction'at an angle of 120 degrees, or substantially 120 degrees, to flat 8. Flat 9 serves a positioning function and does not constitute a driving element of the wrench as shown. Flat 9 is in such position, however, thatit would be available to conwrench might be undesirably large and unwieldy E the smallest shape.

While the wrench is shown and described as having flats for engaging the hexagonal shapes, it will be una derstood that this term is used to define a surface portion for engagement against a corresponding surface of the shape to be turned, and while it is not essential that each flat be absolutely flat or that it be entirely free from interruptions in the surface, it should make flat contact throughout most of its extent with the surface of the hexagonal shape whereby to transmit force thereto over a substantial area and thereby avoid damage to the shape and wrench. Thus it is preferred that each flat should be uninterrupted to provide optimum contact area.

It will be noted that the angles of the flats are stated to be substantially 1-20 degrees or 240 degrees, and at approximately 30 degrees to the center line 16. The optimum flat positions are those which, when the wrench is in use to exert force on the shape being turned, will cause the respective flats to engage flat against the respective shape surfaces. The application of substantial turning force will, however, cause a slight separation between the jaws because of the resultant deformation of the wrench. The extent of the deformation will, of course, depend upon the amount of force being applied, the material and specific shape of the wrench, and other factors. And there will be greater deformation when turning large shapes near the forward ends of the jaws with large turning force being applied than for smaller shapes engaged by rearwardly disposed flat portions of the jaws. There will also be a much less important but in some cases appreciable deformation of the hexagonal shape itself. The usual open end wrench has flats extending completely along both of the two opposite faces of a hexagonal shape which is to be turned, which flats must be separated by more than the distance between the faces to be engaged in order for the wrench to he slipped into place, and, therefore, as a matter of geometry, the contact between the wrench flats and the hexagonal shape faces is limited to the extreme ends of the faces. In contrast, the flats of the present wrench may be and preferably are so disposed as to be, when a designed maximum force is applied to any one of the several sizes of hexagonal shapes, in flat engagement against the respective surfaces of the hexagonal shape being turned.

For example, the wrench in FIG. 1 is shown in engagement to turn a hexagonal shape 27, with Hat 7 in contact with face 28 of the shape and flat 11 in contact with the opposite face 29. If the original contact, before turning force is applied, between flat 7 and face 28 occurs at the inward rearward terminus 25 of flat 7, and if the original contact between flat 11 and face 29 occurs at the inward forward terminus 15 of flat 11, the application of force which causes the jaws to spread slightly apart will, if the wrench is properly designed in accord with this oncept, cause the flats to assume the positions shown wherein each is in flat engagement with the respective face of the hexagonal shape.

Wrenches in accordance with this invention will provide driving contact along substantially less than one-half of each of the opposite faces of the hexagonal shape engaged by any two driving flats, as hereinafter explained, but when the flats of the Wrench are so disposed as to compensate for the deformation of the jaws as explained above, the area of driving contact will be greater than that obtainable with the usual open end or movable jaw monkey wrench.

The specific design of a hexagonal wrench, that is, a wrench adapted for turning hexagonal shapes, embodying the advantages of applicability to a plurality of sizes of shapes and having the ability to ratchet on each shape of the range of sizes, requires that the spacing between edges formed by intersecting flats which point or are directed inwardly between the jaws, which edges are on opposite jaws, should be such as to prevent a larger hexagonal shape of the range from slipping, during ratcheting, into the position intended to receive the next smaller shape. As seen in FIG. 1, for example, the wrench is positioned to rotate shape '27, shown in full lines, in a clockwise direction, with flat 7 of the wrench engaging face 28 of the shape in a position to push the face .28 and with flat 11 engaged against face 29 in a position to pull the face 29. When the wrench is rotated from the driving position of FIG. 1 in a counterclockwise direction, the wrench takes upsuccessive positions represented by broken lines in FIG. 2, and during this backing of the wrench for a new grip on the shape, the shape 27 should not be permitted to slide between edges 14 and 25. In other words, the distancebetween edges 14 and 25 should be less than the width of shape 27, as measured between opposite faces of the shape, such as between faces 28 and 29. Similarly the distance between edges 15 and 25 should be less than the width of the shape of the series which is next larger than shape 27, that is to say, shape 19.

FIG. 1 shows a third shape 30 in broken lines which is drivingly engaged on its opposite faces 31 and .32 for counterclockwise rotation by flats 8 and 12. Flat 9 of the wrench, as stated above, has no force-applying function but serves to position and guide the shape 30 with respect to the wrench, or to position and guide the wrench with respect to the shape. 7

The wrench l is arranged to ratchet on each of the hexagonal shapes which it is adapted to rotate, and the wrench is shown in several positions successively assumed during ratching from one driving position into a new driving position on shape 27 in FIG. 2. As seen therein, with the wrench 1 in full line position on the hexagonal shape, the wrench is positioned to drive the shape in a clockwise direction. When the wrench is moved in a counterclockwise direction, while at the same time being gently urged toward the shape, jaw 4 moves forward and jaw 3 rearward into the broken line position a, with the corner 33 of shape 27 moving along fiat I2 and maintaining edge 15 out of contact with the shape, and with edge 25 moving along face 23' of the shape and maintaining edge 22 out of contact with the shape. This movement proceeds until edge 25 clears the corner 3-l at the end of face 28 of shape 27 as shown by the wrench position b. At this position, when edge 25 clears corner 34-, the corner 33 of the shape must still be engaged with flat 12 and edge 15 must still be out of contact with the shape, because, if edge 15 met face 29 before edge 25 cleared corner 34, the Wrench would be locked on the shape and, upon further rotation, would not freely ratchet on the shape but would undesirably impose turning force on the shape.

The edge 25 having now cleared corner 34, as the wrench is turned beyond the b position, corner 34 rides along flat 7, as represented by position 0, until flat 11 passes corner 35 of the shape and can slide up into a position against face 36 of the shape with flat'7 engaged against the opposite shape face 37. It will be .seen that edge 15 must pass corner 35 before fiat 6 becomes engaged with face 28, to prevent the Wrench from becoming locked. When flat 11 has engaged face 36, and with a portion of flat 7 engaged against face 37', the wrench will be again in operative turning relation to the hexagonal shape.

A similar sequence will occur for either of shapes 19 and 30, although it will be apparent that with the wrench oriented as shown in FIGS. 1 and 2 it will rotate shapes 19 and 30 in a left hand or counterclockwise direction. The wrench 1 is shown in FIG. 3 other side up, and in this position it is operative to rotate shape 27 in left hand or counterclockwise rotation. In this position, of course, it would be operative to rotate'shape 19 or shape 30 clockwise.

In order for the wrench to be operative on each of a series of three or more progressive sizes of hexagonal shapes, it is necessary that certain geometric relationships obtain. In any embodiment of the wrench, it is preferable that the areas of contact of the wrench flats in driving engagement with the opposite faces of any one shape be equal, because the maximum turning force which can be transmitted would normally be determined by the area of contact of that one of the operative flats which contacts the smaller area of the shape face, and in designing the wrench, if one of the flats which is in operative force-applying contact with a particular shape has a larger area of contact than the other similarly engaged forceapplying operative flat, it will be possible by some redesign-ing to increase the area of contact of the flatWi-th less area of contact while reducing the area of contact of the other fiat and by so doing to provide a wrench with improved distribution of forces as between the flats.

It will be apparent that, for a shape 19 to be engaged by flats 6 and 10, the edge 21 must be spaced from edge by a distance which is less than the diagonal dimension, from one to an opposite corner, of shape 19, or in other words, less than 1.1547 times the width dimension of shape 19. Similarly, the distance from edge 24 to edge 25 must be less than the secant of degrees, or 1.1547, times the width dimension of shape 27 in order for flats 7 and 11 to engage this shape, and the distance from edge 14 to edge 26 must be less than 1.1547 times the Width dimension ofshape 30 for flats 8 and 12 to drivingly engage that shape. The value of the secant of 30 degrees -is sometimes given herein as 1.155 for simplicity, and

since greater precision is probably impractical in usual wrench construction.

The positioning flat 9 extends from edge 26 inwardly and rearwardly to within a distance from edge 14 less than the width dimension of shape 30. As seen in FIG. 1, if the wrench is rotated clockwise to ratchet on shape 30, the corner 37 will travel along flat 9 until corner 38 clears edge 14. This will occur just as corner 37 reaches a point at approximately the location 39 along flat 9. If a point 39 along flat 9 from edge 26 is located less than the width dimension of shape 30 away from edge 14, shape 30 cannot pass rearwardly toward the handle 2 beyond points 14 and 39, and it is not material what shape exists between these points and the handle so long as space is provided to clear the corners of the hexagonal shape during ratcheting of the wrench on the smallest of the shapes with which it is designed to operate.

The wrench is preferably designed to provide an area of contact for a pushing flat, such as portion 17 of flat 10, for each given size of hexagonal shape, equal to the area of contact of the corresponding pulling flat, in this case, flat 6. Similarly, flat 11 ,a pulling flat, should have an area of contact with face 29 of shape 27 equal to the area of contact of flat 7 with face 28. To accomplish such preferred distribution, the wrench is designed for hexagonal shapes of a series of sizes, having width dimensions between parallel opposite faces which may be designated A, B, C and D, respectively, wherein The series may .theoretically continue indefinitely, but wrenches designed for a series of more than 4 or 5 sizes have jaws which extend inconveniently far beyond the smallest shape of the series and which may be undethat edges 25 and 14 be spaced apart by less than the' width dimension of shape 27, and that similar relationships exist for other shapes'of the series. For a series of shapes having widths of A, B and C in accord with the above limits, for a wrench wherein the pushing and pulling flats engage equally, the wrench will comprise a pair of jaws 3 and 4 as described above, wherein flat 10 6 extends forwardly and outwardly for at least a distance of 1.155 (AB) (or 1.1547 (A-B)), wherein flat 6 extends from edge 21 to edge 22 a distance of 1.155 (A-B), terminating in edge 22 which is spaced from edge 15 by a distance greater than 1.0344A, and wherein flat 7 extends from edge 21 to edge 25 and edge 25 is spaced from edge 15 by a distance which is less than width dimension 'A and more than 1.034B, and flat 11 extends from edge 15 a distance equal to 1.155 (BC). In order that the area along flat 7 engaged with shape 27 should be equal to the area engaged by flat 11, it will be found that edge 24 should be distant from edge 25 by the diagonal of B less 1.1547 (BC) times sine 30, or- (1.l547B)(.5 1.1547 (BC)), which simplifies to .577 (B-i-C). The wrench will further comprise the flat 12 extending from edge 24 to edge 14, with edge 14 distant from edge 25 by less than the dimension B, and by more than 1.034C whereby ratcheting on shape C is permitted, and with flat 8 extending from edge 25 to edge 26 a distance less than .155C and with the distance 1 between edges 14 and 26 being equal to 1.1547C-sine 30 times the distance from edge 25 to edge 26, whereby the contact area from edge 25 to edge 26 is equal to the contact area along flat 12 from edge 14. Similar provision could, of course, be made for shapes D, E N of decreasing widths, with flat 8 then being 1.1547 (CD) and the distance from edges 14 to edge 25 being .577 (C+D), and with additional flats being provided following along with the progression as given.

While a wrench in accord with the requirements of the paragraph next above will provide optimal characteristics in the respect that the contact areas of the operative flats engaging opposite faces of each shape will be equal, it is not essential that a wrench for hexagonal shapes beso designed and a wrench will be operative if the length of fiat 11, from edge 15 to edge 24, is less than:

.but it will be apparent that there is no necessary minimum length for the flat 6. It would be theoretically possible to cut back flat 6 to a very small length approaching -zero length.

As to the pulling flat for intermediate sizes of hexagonal shapes, each must fall within the minimum and maximum limits as given in the above formula, but as to the smallest hexagonal shape of the series, which would be shape 30 of FIG. 1, having the width C, there would be no required minimum, although some clearance 1 space must be provided to permit ratcheting of shape 27 which is in the embodiment shown provided by the setback of flat 9 from alignment with flat 7. Otherwise, the flat 8 may be very short and engage only a very small part of face 3-1 adjacent corner 37 of the shape. It will also be apparent that, in the wrench of FIG. 1, flat 8 could, without causing the wrench to be inoperative, be

extended outwardly and rearwardly if flat 12 were also extended inwardly and rearwardly. Moving edge 14 to its minimum allowance distance from edge 25 or 7 1.0340, fiat 12 must be terminated just before its edge '14 reaches a position at a distance equal to 1.034C from edge 25.

Wrenches arranged in accord with the maximum and minimum pulling flat lengths as given above, however, will not necessarily have equal pulling and pushing contact with any given shape, and will not necessarily make optimum use of wrench material or size.

In addition to falling within the maximum and minimum value given, it will also be necessary that the opposed succeeding inwardly directed edges be spaced apart 7 on the opposite jaws by a distance less than the width dimension of the shape which it is desired should not enter between the edges. In other words, specifically, edges 15 and 25 must, for any wrench which is to ratchet on shape 19, be spaced apart by a distance less than the width dimension of shape 19, and, similarly, edge 25 must be spaced from some part of fiat 12, such as edge 14, by a distance less than the width dimension of shape 27.

In order to rotate the hexagonal shape 27 clockwise, the wrench is positioned as shown in FIGS. 1 and 2. In this position it would operate to rotate shape 19 counterclockwise. It will be apparent from FIG. 3 that by simply turning the wrench over it will operate to rotate shape 27 in. a counterclockwise direction. Thus, if it is desired to rotate any particular shape in one direction and it is found that the wrench when positioned rotates the shape in the undesired direction, it is only necessary to invert the wrench to give the desired result.

It will thus be seen that the wrench of FIGS. 1-3 comprises jaws 3 and 4 each with a series of flats. The flats of jaw 4 meet each otherin angles which alternate between an angle equal to the included angle between adjacent sides of the hexagonal shape and the supplement of such included angle plus 180 degrees. Since the included angle between adjacent faces of a hexagonal shape is 120 degrees, the reflux angle between flat and flat 11 of jaw 4 is equal to 180 degrees plus the supplement of 120 degrees, or 240 degrees, and the angle between flat 11 and flat 12 is equal to the included, angle, or 120 degrees. If a smaller shape was to be included in the series, fiat 12 would make an angle equal to 240 degrees with the next flat of jaw 4. The flats 10, 11, 12 of jaw 4 are parallel respectively to corresponding alternate flats 6', 7, 8 of jaw 3, and flat 6 meets flat 7 in an angle equal to 120 degrees, flat 7 meets fiat 8 in a reflex angle equal to 240 degrees, and flat 8 meets flat 9 in an angle equal to 120 degrees. The pair of flats 8 and 12 for driving engagement of the smallest shape 30 are spaced apart by a distance equal to the width dimension C of this shape, and the distance between the flats of each pair from the closest pair 8 and 12, nearest handle 2, increases for each succeeding pair, pair 7 and 11 and finally pair 6 and 10 nearest the forward ends of jaws 3 and 4.

As specific example, a typical wrench embodying the invention may be proportioned in accord with the above described relationships to accommodate hexagonal shapes of seven-sixteenths, one-half, nine-sixteenths and fiveeights inch sizes, or for five-sights, three-quarters, seveneighths, one inch and one and one-eighth or one and onequarter inch sizes. It will be understood'that these examples are not intended to be limiting, that metric series are practical, and that the wrench may be designed for operation on hexagonal shapes of much smaller or much larger sizes and of greater or less numbers of sizes in the series for which the individual wrench is designed.

In instances of insufficient or excessive size differences in a series, substitution of the dimensions thereof in the formulas will reveal impractical or even impossible maximum minimum restriction. In the event of insufficient size differences rearrangement of the series may be necescontact areas, it is possible to slightly round the edges 22, 15 and to thereby increase the spacing from, for example, edge 22 to edge 15, or from edge 15 to edge 25, or from the edge 25 to edge 14, whereby the permissable difference between one size and the next of the series may be slightly increased. Thus, if the spacing between edges 15 and 25 to fulfil the design requirements for equal push and pull flat areas on shape 27, and to accommodate a shape which was too small to be within the series limits given, the edges 15 and 25 could be rounded to be distant by 1.034B (thereby to permit ratcheting on shape 27 or B) and yet permit accommodation of the undersize shape 30 or C. This would reduce push area on shape 19 or A, and would reduce both push and pull contact areas on shape B and pull area on shape C.

The wrench 39 of FIGS. 4 and 5 is arranged to ratchet on square shapes, although somewhat less readily than the wrench for hexagonal shapes. It is proportioned and arranged to engage square shape 40, shown in solid lines, and a larger and a smaller shape of the series, shapes 41 and 42, respectively, which are represented in broken lines. The forwardmost pair of corresponding flats 43 on jaw 44 and 45 on jaw 46 are spaced apart by a perpendicular distance equal to the width dimension A of the largest member 41 of the series of square shapes for which the wrench is designed to operate. Flat 43 extends outwardly and rearwardly to an edge 47 at which it meets flat 48 and terminates forwardly in an edge 49 be yond which the jaw is relieved. The angle between flats 43 and 48 measured inwardly of the space between the jaws is equal to the angle included between each and the next adjacent face of the shape which the wrench is designed to accommodate, and, this shape being square, the angle is 90 degrees.

Flat 48 extends from edge 47 inwardly and rear-wardly terminating at edge 50 at which it meets flat 51 in an angle measured inwardly of the space between the jaws, i.e., the reflex angle between flats 48 and 51, equal to the supplement of the angle between adjacent sides of the shape plus 180 degrees, in this case 270 degrees. Plat 51 extending from edge 50 rearwardly and outwardly terminates at edge 52 where it meets the next flat 53 in an angle of 90 degrees.

Jaw 46 is provided with a series of flats including flat 45 meeting flat 5 4 at edge 55 at an angle of 2 degrees, flat 54 meeting flat 56 at edge 57 at an angle of degrees and flat 56 terminating rearwardly at edge 58, the jaw being relieved rearwardly and outwardly of edge 58 as seen at 59. It will be seen that alternate flats of each jaw, such as flats 45 and 56 of jaw 46, are parallel to each other and to flats 43 and 51 of jaw 44, and that these flats 43, 56 and 51, respectively, are at an angle to the other flats 48, 54, 53, which in each case is equal to the supple ment of the angle included between adjacent faces of the shapes, or 90 degrees.

For reasons similar to those discussed above in connection with the wrench for hexagonal shapes, the wrench of FIGS. 4 and 5 should have a distance between edges 50 and 55 equal to less than the width A of the largest square shape 41, a distance between edges 49 and 55 equal to more than A and less than the diagonal dimension of the shape 41; that is 1.414A. Similarly, the edges 50 and 55 are spaced by a distance less than 1.414B', where B is the Width of shape 40, and greater than B, while edges 50 and 58 are spaced by a distance equal to more than C,- the width of shape 42, and less than 1.414C'.

In order to permit ratcheting of wrench 39 on the several shapes, in an embodiment permitting equal contact .areas in the operative flats engaging opposite faces, i.e.

providing optimum engagements, itis necessary that If the wrench were designed for a next smaller shape D, then it would be necessarythat and so forth.

The manner in which wrench 39 ratche-ts on shape 40 is shown in FIG. wherein the wrench is shown in driving engagement, for clockwise rotation, in solid lines at 39.

In broken line position 60, edge 50 is sliding along face 61 of the shape with edge 55 not inv contact with the opposite face 62, but with corner 63 of the shape engaged with and sliding along flat. It isnecessary that edge 50 clear the end of face 61 at corner 64, as demonstrated by the broken line position 65, before edge 55 contacts face 62, for otherwise the wrench would jam. After edge 50 has cleared corner 64, the wrench movesinto position shown in broken lines at 6'6, with corner 64 sliding along flat 48 until flat 54 has cleared corner 67, and, can engage face portion 68 of the shape, whereupon all is prepared for the next turning step.

It will be noted that, while the wrench for the hexagonal shapes can be continuously urged toward the shape, in ratcheting on square shapes the wrench must move slightly away from the shape, ina rearward direction, between the positions shown at 60 and 65, approximately. With the square shape, the wrench need not be removed from contact with the shape while ratcheting to a new position, but the user must move it rearwardly to permit it to follow along the shape, whereas, with the hexagonal shapes, the wrench is cammed away automatically as it is ratcheted to a new position and one may, therefore, continuously urge it toward the shape while swinging it in the ratcheting direction.

In order for the ratcheting operation as described to be accomplished, and for the wrench to be arranged to have, on each shape being turned, optimum driving ensimilarly, spaced from edge 55 by at least a distance equal to 1.083B and by a distance, as previously mentioned, which is less than A. With reference to FIG. 5, if the distance from edge 50. to edge 55 was equal to less than 1.08-3B', the edge 50 would not clear the corner 64 (as seen in position 65) during ratcheting before edge 55 engagedface 62, and, therefore, the wrench would jam and not ratchet.

The appropriate length of flat 54 is B'C'.

Edge 50 is'spaced from edge 58 bya distance equal to at least l.l08 3C-but less than B. The length of flat 51 is equal to less than .293C and should be close to this value, although the wrench would be operative with only a very short flat 51.

While, as in the wrench for hexagonal members, the

wrench for square members proportioned as described above will provide optimal characteristic in the respect that the contact area of the operative flats engaging opposite faces of each shape will be equal, it isnot essential 1 and the length of flat 54 is C'-- /(A') (B') The wrench 39 must also have a pulling flat 43 which is but it will be apparent that there is no necessary minimum length for flat 4 3, as there was no necessary minimum length for fiat 6 in FIG. 1 in the embodiment for hexagonal shapes. Similarly, there is no necessary minimum length for flat 51, as there was no necessary minimum length for flat 8 in the hexagonal wrench embodiment.

While only certain preferred embodiments of this invention have been shown and described by way of illustration, many modifications will occur to those skilled in the art and it is, therefore, desired that it be understood that it is intended in the appended claims to cover all such modifications as fall wtihin the true spirit and scope of this invention.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is:

1. An open end wrench for use with rotatable members of a series of sizes of a predetermined regular polygonal shape having even numbers of sides, said wrench comprising a handle and a pair of jaws extend ing forwardly from one end of the handle and generally outwardly from each other, said jaws having stepped inner faces comprising a series of flats for engaging sides of said members, each flat of each jaw meeting the next adjacent flat in an angle and said angles of each jaw alternating between an angle equal to the included angle between adjacent sides of said predetermined shape and a reflex angle equal to the supplement of such included angle plus 180 degrees, alternate said flats of each jaw being parallel to each other and to respective corresponding alternate flats of the other jaw and at an angle to the other flats of said other jaw equal to the supplement of said included angle, the flats of each pair of said corresponding flats being spaced apart by perpendicular distance equal to the width of a respective one of said series of sizes and said distance increasing for each said pair of flats from the closest pair nearest the handle to the greatest spacing for the pair nearest the forward ends of the jaws.

2. An open end wrench for use with rotatable members of a series of sizes of hexagonal shape, said wrench comprising a handle and a pair of jaws extending forwardly from one end of the handle and generally out wardly from each other, said jaws having stepped inner faces comprising a series .of flats for engaging sides of said members, each flat of each jaw meeting the next adjacent flat in an angle and said angles of each jaw alternating between an angle equal to degrees and a reflex angle equal to 240 degrees, alternate said flats of each jaw being parallel to each other and to respective corresponding alternate flats of the other jaw and at an angle to the other flats of said other jaw equal to 60 degrees, the flats of each pair of said corresponding flats being spaced apart by a perpendicular distance equal to the width of a respective one of said series of sizes and said distance increasing for each said, pair of flats from the closest pair nearest the handle to the greatest spacing for the pair nearest the forward ends of the jaws.

3. An open end wrench, for use with hexagonal-headed rotatable members of three progressive sizes having widths between parallel sides designated A for the largest, B for the next smaller and C for the next smaller size, said wrench comprising a pair of jaws with stepped inner faces each comprising a series of flats for engaging sides of said members, said jaws extending forwardly from one end of a handle and generally outwardly from each other, the outermost pair of opposed flats comprising a first flat at the outer end of one jaw extending from an edge a forwardly and outwardly of the space between the jaws, and a second flat on said other jaw parallel to said first flat and spaced therefrom perpendicularly by a distance equal to A and extending from an edge c forwardly and inwardly of the space between distance from'edge a the jaws to an edge b distant from c by a distance equal to or less than said other jaw being relieved beyond edge b, and the to edge .c being 1.155A, a third flat on said one jaw extending from edge a rearwardly and outwardly of the space between the jaws at an angle of substantially 240 to said first fiat and terminating in an edge d, a fourth flat on said other jaw parallel to said third flat and spaced therefrom by the perpendicular distance B and extending from edge rearwardly and inwardly of the space between the jaws and terminating rearwardly in an edge e such that the distance from edge a to edgefe is A, the length of the third flat from edge a to edge "d being equal to or less than and equal to or more than l.155C.577B /A B the distance from edge d to edge e being 1.155-B, a fifth Hat on said first jaw extending from edge d at an angle of substantially 120 to the third flat rearwardly and inwardly of the space between the jaws and terminating in an edge f rearwardly of which the jaw is relieved in a direction outwardly of the space between the jaws, a sixth flat on said other jaw parallel to and spaced from said fifth flat by a perpendicular distance equal to C and extending from edge e to an edge g, the length of the sixth flat from edge e to edge g being appreciable and .155C, and a guiding seventh flat on said other jaw' extending from edge g at an angle of substantially 120 to said sixth flat rearwardly and inwardly of the space between said jaws for locating a said member C when such member is in driving engagement between said fifth and sixth flats, the distance between edges e and being B and the distance from edge f to edge g being 1.155C.

4. An open end wrench, for use with hexagonal-headed threaded members of progressive sizes having widths between parallel sides designated A for one such size and B for the next smaller size, wherein B is less than substantially .966A, said wrench comprising a pair of jaws with stepped inner faces each comprising a series of flats for engaging sides of said members, said jaws extending forwardly from one end of a handle and generally outwardly from each other, the outermost pair of opposed flats comprising a first flat at the outer end of one jaw extending from an edge a forwardly and outwardly of the space between the jaws, and a second flat on said other jaw parallel to said first flat and spaced therefrom perpendicularly by a distance equal to A and extending from an edge c forwardly and inwardly of the space between the jaws to an edge b, said other jaw forwardly of said edge b being relieved in a direction outwardly of the space between the jaws, a third flat on said one jaw extending from edge a rearwardly and outwardly of the space between the jaws at an angle of substantially 240 to said first fiat and terminating in an edge d, a fourth flat on said other jaw parallel to said third flat and spaced therefrom by the perpendicular distance B and extending from edge 0 rearwardly and inwardly of the space between the jaws and terminating rearwardly in an edge e such that the distance from edge a to edge e is l.034B A, said other jaw rearwardly of said edge e being relieved in a direction outwardly of the space between the jaws, and a guiding fifth flat on said one jaw extending from edge d at an angle of substantially 120 to the third flat rearwardly and inwardly of the space between the jaws and approaching to within a distance less than that equal to B from the ed'ge"e for locating and guiding a said member of size B when such member is in driving engagement between said third and fourth flats.

5. An open end wrench, for use with hexagonal-headed threaded members of three progressive sizes having width dimensions between parallel sides designated A for the largest, B for the next smaller and C for the next smaller size, wherein, substantially,

said wrench comprising a pair of jaws with stepped inner faces each comprising a series of flats for engaging sides of said members, said jaws extending forwardly from one end of a handle and generally outwardly from each other, the outermost pair of opposed flats comprising a first flat at the outer end of one jaw extending from an edge a forwardly and outwardly of the space between the jaws at least for a distance of substantially 1.155(A -B), and a second flat on said other jaw parallel to said first flat and spaced therefrom perpendicularly by a distance equal to A and extending from an edge 0 forwardly and inwardly of the space between the jaws to an edge b distant from edge a by at least 1.0344A, said other jaw being relieved beyond edge b, the distance from edge a to edge c being 1.1-547 A, a third flat on said one jaw extending from edge a rearwardly and outwardly of the space between the jaws at an angle of substantially 240 to said first flat and terminating in an edge d, a fourth flat on said other jaw parallel to said third fiat and spaced therefrom by the perpendicular distance B and extending from edge e rearwardly and inwardly of the space between V the jaws and terminating rearwardly in an edge e such that the distance from edge a to edgee is 1.034B A, the length of the third flat from edge a to edge d being equal to substantially 1.155 (BC), the distance from edge d to edge a being equal to substantially .577B+.577C, a fifth flat on said first jaw extending from edge d at an angle of substantially to the third flat rearwardly and inwardly of the space between the jaws and terminating in an edge f rearwardly of which the jaws is relieved in a direction outwardly of the space between the jaws, a sixth flat on said other jaw parallel to and spaced from said fifth flat by a perpendicular distance equal to C and extending from edge e to an edge g, the length of the sixth flat from edge e to edge g being appreciable and .l55C, and a guiding seventh flat on said other jaw extending from edge g at an angle of substantially 120 to said sixth flat rearwardly and inwardly of the space between said jaws for locating a said member of size C when such member is in driving engagement between said fifth and sixth flats, .said seventh flat extending to within a distance less than C to edge f, the distance between edges 2 and f being 1.034C B and the distance between edges and g being 1.155C.

6. An open end wrench for use with rotatable members of a series of sizes of square shape, said wrench comprising a handle and a pair of jaws extending forwardly from one end of the handle and generally outwardly from each other, said jaws having stepped inner faces comprising a series of flats for engaging sides of said members, each flat of each jaw meeting the next adjacent flat in an angle and said angles of each jaw alternating between an angle equal to ninety degrees and a reflex angle equal to 270 degrees, alternate said flats of each jaw being parallel to each' other and to respective corresponding alternate flats of the other jaw and at an angle to the other flats of said other jaw equal to ninety degrees, the flat of each pair of said corresponding flats being spaced apart by a perpendicular distance equal to the width of a respective one of said series of sizes and said distance increasing for each said pair of flats from the closest pair nearest the handle to the greatest spacing for the pair nearest the forward ends of the jaws.

7. An open end. wrench, for use with square-headed 13 threaded members of three progressive sizes having width dimensions between parallel sides designated A for the largest, B for the next smaller and C for the next smaller size, wherein, substantially, Bg.707A .925A and C 2 .707B .925Bg.5A, said wrench comprising a pair of jaws with stepped inner faces each comprising a series of flats for engaging sides of said members, said jaws extending forwardly from one end of a handle and generally outwardly from each other, the outermost pair of opposed flats comprising a first flat at the outer end of one jaw extending from an edge a forwardly and outwardly of the space between the jaws at least for a distance of substantially (A-B), and a second flat on said other jaw parallel to said first flat and spaced therefrom perpendicularly by a distance equal to A and extending from an edge forwardly and inwardly of the space between the jaws to an edge b distant from edge a by at least 1.083A, said other jaw beingrelieved beyond edge b, the distance from edge a to edge 0 being l.4l4A, a third fiat on said one jaw extending from edge a rearwardly and outwardly of the space between the jaws at an angle of substantially 270 degrees to said first flat and terminating in an edge d, a fourth flat on said other jaw parallel to said .third fiat and spaced therefrom by the perpendicular distance B and extending from edge 0 rearwardly and inwardly of the space between the jaws and terminating rearwardly in an edge e such that the distance from edge a to edge e is l.O83B A, the length of the third flat from edge a .to edge d being equal to substantially (BC), the distance from edge d to edge e being 1.4l4B, a fifth flat on said first jaw extending from edge d at an angle of substantially 90 degrees to the third flat rearwardly and inwardly of the space between the jaws and terminating in an edge f rearwardly of which the jaws is relieved in a direction outwardly of the space between the jaws, a sixth flat on said other jaw parallel to and spaced from said fifth flat by a perpendicular distance equal to C and extending from edge e to an edge g, the length of the sixth flat from edge e to edge g being appreciable and .293C, and a guiding seventh flat on said other jaw extending from edge g at an angle of substantially 90 degrees to said sixth flat rearwardly and inwardly of the space between said jaws for locating a said member of size C when such member is in driving engagement between said fifth and sixth flats, said seventh flat extending to within a distance less than C to edge f, the distance betwen edges e and f being 1.083C B and the distance between 8. An open end wrench, for use with square-headed threaded members of progressive sizes having widths between parallel sides deisgnated A for one such size and B for the next smaller size, wherein B is less than substantially .925A, said wrench comprising a pair of jaws with stepped inner faces each comprising a series of flats for engaging sides of said members, said jaws extending forwardly from one end ofa handle and generally outwardly from each other, the outermost pair of opposed flats comprising a first flat at the outer end of one jaw extending from an edge a forwardly and outwardly of the space between the jaws, and a second flat on said other jaw parallel to said first flat and spaced therefrom perpendicularly by a distance equal to A and extending from an edge c forwardly and inwardly of the space between the jaws to an edge b, said other jaw forwardly of said edge b being relieved in a direction outwardly of the space between the jaws, a third flat on said one jaw extending from edge a" rearwardly and outwardly of the space between the jaws at an angle of substantially 270 degrees to said first flat and terminating in an edge d, a fourth flat on said other jaw parallel to said third flat and spaced therefrom by the perpendicular distanceB and extending from edge c rearwardly and inwardly of the space between the jaws and terminating rearwardly in an edge e such that the distance from edge a to edge e is l.083B A, said other jaw rearwardly of said edge e being relieved in a direction outwardly of the space between the jaws, and a guiding fifth flat on said first jaw extending from edge d at an angle of substantially degrees to the third flat rearwardly and inwardly of the space between the jaws and approaching to within a distance less than that equal to B from the edge e for locating and guiding a said member of size B when such member is in driving engagement between said third and fourth flats.

9. An open end wrench, for use with square-headed rotatable members of three progressive sizes having widths' between parallel sides designated A for the largest, B for the next smaller and C for the next smaller size, said wrench comprising a pair of jaws with stepped innerfaces each comprising'a series of flats for engaging sides of said members, said jaws extending forwardly from one end of a'handle and generally outwardly from each other, the outermost pair of opposed flats comprisingv a first flat at theouter end of one jaw extending from an edge a forwardly and outwardly of the space between the jaws, and a second flat on said other jaw parallel to said first flat and spaced therefrom perpendicularly by a distance equal to A and extending from an edge 0 forwardly and inwardly of the space between the jaws to an edge b distant from c by a distance equal to or less than rim-AME? said other jaw being relieved beyond edge b, and the distance from edge a to edge 0 being 1.414A, a third flat on said one jaw extending from edge a rearwardly and outwardly of the space between the jaws at an angle of substantially 270 degrees to said first flat and terminating in an edge d, a fourth .flat on said other jaw parallel to said third flat and spaced therefrom by the perpendicular distance B and extending from edge 0 rearwardly and inwardly of the space between the jaws and terminating rearwardly in an edge e such that the distance from edge a to edge e is A, the length of the third flat from edge a to edge d being equal to or less than tending from edge e to an edge g, the length of the sixth flat from edge e to edge g being appreciable and .293C, and a guiding seventh flat on said other jaw extending from edge g at an angle of substantially 90 degrees to said sixth flat rearwardly and inwardly of the space between said jaws for locating a said member C when such member is in driving engagement between said fifth and sixth flats, the distance between edges e and f being B and the distance from ,edge f to edge g being 1.4l4.

10. A wrench comprising a pair of spaced jaws for turningly engaging opposite faces of a series of predetermined sizes of rotatable members of a regular polygonal shape having an even number of sides, each inner jaw face comprising a plurality of flats facing toward the respectively opposite face and each operative flat of each jaw cooperative with a respective parallel flat of the other jaw and said cooperative flats being spaced apart to drivingly engage portions of opposite faces of a respective member of said series; such portions comprising portions adjacent respectively opposite corners of the member and extending in each case from the corner not more than about onethird of the member face, and each said flat terminating at an intersection with a flat for the next size member of the series.

References Cited by the Examiner UNITED STATES PATENTS 2,334,069 11/1943 Collins et a1. 8190 2,671,368 3/1964 Diebold 811l9 16 FOREIGN PATENTS 478 1872 Great Britain. 125,021 4/1919 Great Britain.

5 WILLIAM PELDMAN, Primary Examiner.

MILTON S. MEHR, Examiner. 

1. AN OPEN END WRENCH FOR USE WITH ROTATABLE MEMBERS OF A SERIES OF SIZES OF A PREDETERMINED REGULAR POLYGONAL SHAPE HAVING EVEN NUMBERS OF SIDES, SAID WRENCH COMPRISING A HANDLE AND A PAIR OF JAWS EXTENDING FORWARDLY FROM ONE END OF THE HANDLE AND GENERALLY OUTWARDLY FROM EACH OTHER, SAID JAWS HAVING STEPPED INNER FACES COMPRISING A SERIES OF FLATS FOR ENGAGING SIDES OF SAID MEMBERS, EACH FLAT OF EAHC JAW MEETING THE NEXT ADJACENT FLAT IN AN ANGLE AND SAID ANGLES OF EACH JAW ALTERNATING BETWEEN AN ANGLE EQUAL TO THE INCLUDED ANGLE BETWEEN ADJACENT SIDES OF SAID PREDETERMINED SHAPE AND A REFLEX ANGLE EQUAL TO THE SUPPLEMENT OF SUCH INCLUDED ANGLE PLUSE 180 DEGREES, ALTERNATE SAID FLATS OF EACH JAW BEING PARALLEL TO EACH OTHER AND TO RESPECTIVE CORRESPONDING ALTERNATE FLATS OF THE OTHER JAW AND AT AN ANGLE TO THE OTHER FLATS OF SAID OTHER JAW EQUAL TO THE SUPPLEMENT OF SAID INCLUDED ANGLE, THE FLATS OF EACH PAIR OF SAID CORRESPONDING FLATS BEING SPACED APART BY PERPENDICULAR DISTANCE AND EQUAL TO THE WIDTH OF A RESPECTIVE ONE OF SAID SERIES OF SIZES AND SAID DISTANCE INCREASING FOR EACH SAID PAIR OF FLATS FROM THE CLOSEST PAIR NEAREST THE HANDLE TO THE GREATEST SPACING FOR THE PAIR NEAREST THE FORWARD ENDS OF THE JAWS. 